Grate cooler

Abstract

A grate cooler of simple construction whose cooling grate is substantly protected against wear and which can be operated in simple fashion and with a high cooling efficiency. A plurality of rotatably supported tubular oscillating shafts, spaced apart from one another, are arranged transversely to the conveyance direction of cooling feed material above a stationary cooling grate. Upwardly extending shovel arms ( 16 a , 16 b , 16 c ), are attached to the shafts which move with a reciprocating oscillatory motion ( 17 ) in the conveyance direction of cooling feed material. The shovel arms have a pushing surface on their forward side and a wedge surface on their rearward side and, in their oscillatory motion, moving the hot bed of cooling feed material successively from the beginning of grate-cooler to the discharge of the grate cooler.

What is claimed is:  
     
       1. A grate cooler comprising: 
       a stationary cooling grate ( 12 ) through which cooling gas flows and over which the cooling feed material to be cooled, such as hot cement clinker, can move in a predetermined conveyance direction;  
       a plurality of horizontally extended and rotatably supported tubular shafts ( 15   a ,  15   b ,  15   c ) above said stationary cooling grate ( 12 ) spaced in parallel relation to one another in said conveyance direction and disposed axially transverse to said conveyance direction;  
       upwardly extending shovel arms ( 16   a ,  16   b ,  16   c ) attached at one end to of said tubular shafts ( 15   a ,  15   b ,  15   c ) and presenting a free end, said shovel arms ( 16   a ,  16   b ,  16   c ) executing a fore and aft reciprocating oscillatory motion ( 17 ) in said conveyance direction of said cooling feed material when said tubular shafts are oscillated; and  
       each of said shovel arms ( 16   a ,  16   b ,  16   c ) having a pushing surface ( 18 ) on the forward side of said free end and a wedge surface ( 19 ) on their rearward side.  
     
     
       2. The grate cooler as set forth in  claim 1  wherein forward oscillatory motion of said shovel arms is limited so that said shovel arms do not press said cooling feed material onto said cooling grate. 
     
     
       3. The grate cooler as set forth in  claim 2  wherein the angle between said pushing surface and a plane defined by said cooling grate in said conveyance direction is at least 90°. 
     
     
       4. The grate cooler set forth in  claim 2  wherein during operation of said grate cooler the said oscillating shovel arms ( 16   a ,  16   b ,  16   c ) move in a 70° degree arc. 
     
     
       5. The grate cooler of  claim 1  wherein said shovel arms ( 16   a ,  16   b ,  16   c ) are interchangeably attached to said shafts ( 15   a ,  15   b ,  15   c ). 
     
     
       6. The grate cooler of  claim 5  wherein said shovel arms ( 16   a ,  16   b ,  16   c ) are connected to said shafts ( 15   a ,  15   b ,  15   c ) by key-and-keyway connections ( 20 ,  21 ) including a plurality of keyways ( 20 ,  22 ) formed in said shovel arms ( 16   a ,  16   b ,  16   c ) permitting changes in radial orientation of said shovel arms ( 16   a ,  16   b ,  16   c ). 
     
     
       7. The grate cooler as set forth in  claim 1  wherein said shovel arms ( 16   a ,  16   b ,  16   c ) on one of said shafts ( 15   a ,  15   b ,  15   c ) are staggered in relation to said shovel arms ( 16   a ,  16   b ,  16   c ) on another one of said shafts ( 15   a ,  15   b ,  15   c ). 
     
     
       8. The grate cooler as set forth in  claim 1  wherein said stationary cooling grate ( 12 ) includes cooling-grate segments with troughs or pockets for retaining cooling feed material whereby a lower, precooled bed of said retained material ( 14 ) is maintained on the cooling grate and wherein said oscillating shovel arms ( 16   a ,  16   b ,  16   c ) move the material to be cooled ( 10 ) over said retained material ( 14 ) in the conveyance direction of said cooling grate ( 12 ). 
     
     
       9. The grate cooler of  claim 1  wherein said shovel arms ( 16   a ,  16   b ,  16   c ) each include a wear plate ( 18 ) on which said pushing surface is formed. 
     
     
       10. The grate cooler as set forth in  claim 1  having bearings ( 23 ) and an oscillatory drive ( 24 ) for said shafts ( 15   a ,  15   b ,  15   c ), said bearings ( 23 ) and said oscillating drive ( 24 ) being positioned outside of the lateral walls of said grate cooler. 
     
     
       11. The grate cooler as set forth in  claim 1  wherein said shafts ( 15   a ,  15   b ,  15   c ) are hollow and serve to convey cooling air to said grate cooler.